Summary
Behaviour of a typical multiple impact jarring tool is examined to understand the effect of design and operational parameters on the tool's performance. Low-dimensional models were developed comprising lump masses, springs, and viscous dampers, which can mimic the tool's main function of generating high-amplitude impact forces from the energy stored in the pre-compressed spring. The magnitude and frequency of these impacts are controlled by an overpull and cam mechanisms, respectively. Numerical analysis is performed by direct numerical integration and path-following methods, showing that the system can exhibit co-existing attractors and chaotic behaviour. Parametric studies are carried out to determine the range of design and operational parameters that would enhance the jarring tool performance by generating preferable impact force patterns.
